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June 2021, Vol 104 No. 2

The lanzones scale insect, Unaspis mabilis Lit and Barbecho, is the most serious pest of lanzones nowadays. It has been known to be exclusively associated with this fruit crop since its first reported occurrence in 2009. In this paper, however, a new host record is reported for the first time, the high-valued cacao, Theobroma cacao L. Identification utilized the total evidence provided by both morphological details and molecular analyses.

{Photographs courtesy of C.C. Lucañas of the UPLB Museum of Natural History, K.O. Abenis of the Institute of Biological Sciences, University of the Philippines Los Baños, and Ms. Ruby Ana P. Laude of the Entomology Laboratory, Institute of Plant Breeding, UPLB}

LIST OF ARTICLES

Perceptions on Agriculture among Freshmen Students at the University of the Philippines Los Baños: Key Challenges and Solutions
Kamla Zyra G. Lavadia, Lourdes B. Columbres, Maria Angeli G. Maghuyop, and Domingo E. Angeles 

Received: 12 March 2021/ Revised: 07 May 2021/ Accepted: 26 May 2021

This study involved 832 freshmen students enrolled in the course Introduction to Agriculture from 2009 to 2014 from the College of Agriculture and Food Science and the College of Human Ecology, University of the Philippines Los Baños, to determine the perception of youth towards the field of agriculture and its degree program. Using quantitative parameters and correlation analysis, the relationship between the demographic characteristics and the freshmen’s perception towards agriculture was determined. Students’ demographic characteristics (age and gender) are positively correlated with the student’s perception of agriculture. Initially, the majority (58.3%) of the freshmen have a negative attitude towards the agriculture program. As a student’s in-depth knowledge of the agriculture field increases, their perception and idea of the program is also positively influenced. Contrary to the popular belief that agriculture is a male-dominated field, the majority of the students enrolled in the course are female (63%). Recommendations to make Agriculture more attractive to youth through information dissemination (i.e. ICT-based modalities, infomercials) and interactive campaign will promote the discipline in an effort to increase the interest of the youth and subsequently, the popularity of the program.

Productivity and Profitability of “Turmeric (Curcuma longa) and Okra (Abelmoschus esculentus)” Intercropping System for Marginal Farmers in North-Western Part of Bangladesh
M.R. Islam, M.M. Kamal, M.F. Hossain, J. Hossain, M.G. Azam, and M.S. Islam

Received: 02 September 2020/ Revised: 20 February 2021/ Accepted: 28 March 2021

The agroecological practice of intercropping, meaning farming of two or more crop simultaneously in the same field has recently reaped renewed interest for developing more sustainable cropping and food systems. This technology gained immense interest to marginal farmers of Bangladesh for better economic return from small parcel of their cultivable land. This study evaluated the variants of intercropping system of turmeric (Curcuma longa) and okra (Abelmoschus esculentus) having yield advantage and profitability. The study was conducted during the crop season of 2017 and 2018 at the Regional Agricultural Research Station, BARI, Ishurdi, Pabna, Bangladesh. Five intercropping combination, viz T1 = Turmeric 100% + okra 100%, T2 = Turmeric 100% + okra 90%, T3 = Turmeric 50% + okra 50%, T4 = Sole turmeric (100%), T5 = Sole okra (100%) were studied. The performance of various treatments combination was evaluated based on land equivalent ratio (LER), competitive ratio (CR), monetary advantage index (MAI) and system productivity index (SPI). The findings revealed that intercropping of okra did not affect the rhizome development stage. The T1 and T2 treatment gave 21.85 and 21.59 t ha-1 rhizome yield of turmeric, respectively. Besides, intercropping of okra @ 100 and 90% population (T1 and T2) enhanced 13% and 11% rhizome yield, respectively than the monoculture yield (19.38t ha-1 ). However, the turmeric 100% + Okra 100% intercropping system exhibited maximum turmeric equivalent yield (35.43t ha-1 ), LER (2.12), MAI (4558.61 US$ ha-1) and SPI (44.39). Intercropping indices recommended a positive association of turmeric and okra crops. The study discovered that okra could be introduced as an intercrop with turmeric to increase cropping area and enhance profitability of marginal growers.

Foliar Applied Boron not only Enhances Seed Cotton Yield but also Improves Fiber Strength and Fineness of Cotton Cultivars
Muhammad Ashfaq Wahid, Muhammad Saleem, Shahbaz Khan, Sohail Irshad, Mumtaz Akhtar Cheema, Muhammad Farrukh Saleem, Haroon Zaman Khan, Madad Ali, Ali Bakhsh, Zuhair Hasnain, Sara T. Alrashood, and Sulaiman Ali Alharb

Received: 16 October 2020/ Revised: 23 March 2021/ Accepted: 25 March 2021

Cotton (Gossypium hirsutum L.) is as famous as “White Gold” due to its high quality fiber. Boron (B) is one of essential micronutrients involved directly or indirectly in many plant processes. Cotton growth, yield and quality are intensely influenced with B application. A 2 years field based study was conducted to explore the impact of foliar applied B (0.0, 0.5, 1.0, 1.5, 2.0, and 2.5 kg ha-1) on productivity and quality of cotton cultivars (FH-113, MNH-786, and CIM-496). Outcomes of the experiment reflected that application of various levels of B significantly influences the growth and quality attributes of cotton cultivars. Crop growth rate, plant height, sympodial branches per plant, seed cotton weight per boll, and seed cotton yield were recorded at maximum by application of B at 1.5 kg ha-1 during both growing seasons. Quality parameters including fiber strength and fineness were also improved by foliar application at 1.5 kg ha-1. Among the cotton cultivars, FH-113 performed better regarding productivity, yield and quality of produce during the years of cultivation. Maximum field benefits or net returns were obtained by foliar applied B at 1.5 kg ha-1 in cultivar FH-113 during experimental years. Findings of the current experimentation indicated that foliar application of B at 1.5 kg ha-1 is considered economical to produce good quality of fiber with enhanced seed cotton yield.

Grain Yield Variations in Rice Genotypes Under Different Growing Environments in the Philippines
Kim Nyka C. Perdiguerra, Shiro Mitsuya, Akira Yamauchi, Felino P. Lansigan, Maria Victoria O. Espaldon, Pompe C. Sta. Cruz, and Jose E. Hernandez

Received: 06 April 2021/ Revised: 11 June 2021/ Accepted: 26 May 2021

Grain yield variations in PSB Rc18, NSIC Rc222 (inbreds) and NSIC Rc202H (hybrid) were determined across growing environments as a function of cropping seasons and locations in rice producing areas in the Philippines. Contribution of location to variation in grain yield is 61.0%, while 12.7% for the season, and 6.1% for the genotype and this must be due location by season by genotype interactions. Dry season cropping in Nueva Ecija produced the highest mean grain yield. On the other hand, wet season cropping in Davao del Sur produced the least mean grain yield. The genotypes differed in their response to varying growing environments. NSIC Rc202H is the highest yielder among genotypes during dry season in Nueva Ecija. NSIC Rc222 is the most stable, having relatively high and constant grain yield across environments. High grain yield is associated with aboveground biomass particularly in NSIC Rc202H (R2= 0.8615). Harvest index of NSIC Rc222 has less variations across growing environments, hence, one reason for its relative stability. Among yield components, spikelets per panicle and percent filled spikelets are highly correlated with grain yield (r = 0.85 and r = 0.82, respectively). Grain yield is highly influenced by solar radiation and temperature. Growing degree days (GDD) accumulated by genotypes are generally lower during wet season than dry season. While genotypes with different growth durations may require different GDDs, the higher the GDD accumulated by a particular genotype, regardless of growth duration resulted in higher grain yield, and variations in accumulated GDD is affected directly by temperature and indirectly by solar radiation, contributed to the variations in grain yield across growing environments.

Weedy Rice Conserved Ex Situ Characterized Using Morphological and Simple Sequence Repeat (SSR) Markers
Rubylyn Mijan-Infante, Maria Elizabeth B. Naredo, and Merlyn S. Mendioro 

Received: 21 September 2020/ Revised: 01 March 2021/ Accepted: 11 March 2021

A clear understanding of genetic diversity in weedy rice is important in improving protocols for its conservation, ex situ. To this end, Asian collections of weedy rice together with accessions of the wild AA genome species Oryza nivara Sharma et Shastry and Oryza rufipogon Griffith, and the cultivated species, Oryza sativa L. were characterized using 16 qualitative morphological traits and 18 SSR markers. The Shannon-Weaver index (H’) revealed higher diversity in the weedy (mean H’=0.76) and wild O. nivara (mean H’=0.79) and O. rufipogon samples (mean H’=0.69) compared to the cultivated samples (mean H’=0.44). The weedy forms showed high preference (> 90%) for high grain shattering and awn presence. Cluster analysis based on the 16 qualitative characters revealed three major clusters where weedy accessions grouped with (1) O. rufipogon samples (2) O. nivara, O. rufipogon and indica rice samples, and (3) indica, aus, and japonica and a few O. nivara and O. rufipogon rice samples. Cluster analysis based on SSR data concurred largely with morphological analysis. Genetic diversity indices (number of alleles, observed heterozygosity, expected heterozygosity) detected by SSR markers were comparable between the weedy (1.64, 0.11, 0.23) and O. rufipogon (1.53, 0.19, 0.23) samples. Analysis of molecular variance (AMOVA) among the weedy forms revealed that differentiation within accessions accounted for 79% of the total variation.

Effects of Zeolite on Agronomic and Biochemical Traits and Yield Components of Zea mays L. cv Simone Under Drought Stress Condition
Mehri Salehi, Mehdi Zare, Forood Bazrafshan, Ahmad Aien, and Bahram Amiri 

Received: 09 April 2020/ Revised: 27 February 2021/ Accepted: 28 March 2021

One of the new strategies to increase the effectiveness of chemical fertilizers, prevent waste of chemical fertilizers, also increase the yield of agricultural products, is the use of natural compounds such as zeolite. In this regard, this study was conducted to investigate the effects of zeolite (0, 5, 10, and 15 t ha-1) on agronomic and biochemical responses as well as yield components of maize (cv. Simon) under normal (90% of field capacity), moderate (75% of FC) and severe (60% of FC) drought stress condition during 2017-2019. The results showed that moderate and severe drought stress significantly decreased plant height (in 10.9% and 19.7%, respectively), plant fresh weight (15.2% and 17%, respectively), and plant dry weight (26.7% and 39%, respectively). The highest chlorophyll content reduction was observed under drought stress especially in severe stress (30.7% compared to the normal condition). Application of zeolite improved agronomic (plant height, fresh and dry weight), biochemical (carbohydrate, proline, protein, total phenol, and peroxidase enzyme activity), and yield-related traits under severe drought stress condition. In the other words, zeolite alleviated the effect of drought stress in both consecutive years. So that, application of 10 and 15 t ha-1 zeolite respectively increased grain yield by 20.1% and 61.9% under drought stress compared to control (no application of zeolite). In conclusion, application of 15 t ha-1 zeolite is the suitable treatment to alleviate the negative effect of drought stress on maize (cv. Simon).

RESEARCH NOTE

Enriched Rice Husk Biochar Minimizes Ammonia Loss from Applied Urea Fertilizer Under Waterlogged Environment
Gunavathy Selvarajh, Huck Ywih Ch’ng, Norhafizah Md Zain, and Issariyaporn Damrongrak

Received: 04 August 2020/ Revised: 10 March 2021/ Accepted: 12 March 2021

A laboratory-scale closed dynamic air flow system was carried out to assess the effect of enriched rice husk biochar on ammonia volatilization, soil exchangeable ammonium, and available nitrate from the applied urea in comparison to urea alone under waterlogged conditions. Treatments with enriched rice husk biochar (5, 10, 15, and 20 t ha-1) significantly minimized ammonia volatilization, however, only biochar with rates of 5, 10, and 15 t ha-1 had significantly retained more soil exchangeable ammonium by 14% – 43%. Additionally, soil available nitrate was lower in all treatments except in T1 (urea alone). This indicates that enriched rice husk biochar minimizes ammonia volatilization, retains more ammonium, and slows down the conversion of ammonium to nitrate under a waterlogged environment. Mixing urea with rice husk biochar at rates of 5 t ha-1 and 10 t ha-1 offers a significant advantage over urea alone by minimizing ammonia volatilization by > 33.8% over urea alone. The mixture successfully increased retention of ammonium ions and has the potential to minimize ammonia loss and increase nitrogen availability in the soil.

First Report of the Lanzones Scale Insect, Unaspis mabilis Lit and Barbecho (Hemiptera: Diaspididae), Infesting Cacao, Theobroma cacao L.
Ireneo L. Lit, Jr., Barbara L. Caoili, Merdelyn T. Caasi-Lit, Cristian C. Lucañas, Kristine O. Abenis, Vanessa Kate I. Alvarez, and Romnick A. Latina

Received: 23 December 2020/ Revised: 10 May 2021/ Accepted: 26 May 2021

The lanzones scale insect, Unaspis mabilis Lit and Barbecho (Hemiptera: Diaspididae), is reported to infest cacao trees (Theobroma cacao) in Brgy. Nalook, Kalibo, Aklan. Despite minor morphological differences, analysis of DNA barcode region of the cytochrome c oxidase subunit I (COI) generated from the cacao-infesting scale insects (GenBank Accession Number MN114100.1) matched the DNA barcodes obtained from a complementary study (GenBank Accession Number MN114099), and hence, supported the species identity based on morphological characters. Notes on the distribution, host plant association and insights on possible control measures were provided.

Detection of ‘Candidatus Phytoplasma luffae’ in Sponge Gourd, Bitter Gourd and Bamboo from Laguna in Luzon, Philippines
Filomena C. Sta Cruz, Nuredin Habili, Qi Wu, Rezel B. Sagarino, and John W. Randles

Received: 11 March 2021/ Revised: 10 May 2021/ Accepted: 26 May 2021

In the Philippines, phytoplasma disease symptoms of little leaf and witches’ broom have been observed in sponge gourd (Luffa sp.), bitter gourd (Momordica charantia) and bamboo (Bambusa vulgaris). However, the cause of the disease remained unidentified. Molecular analysis was conducted to detect the presence and identify the phytoplasma associated with the diseased plants. Nested PCR has detected the presence of phytoplasmas in sponge gourd, bitter gourd and bamboo showing symptoms of little leaf and witches’ broom. Nucleotide BLAST and phylogenetic analyses of the 16S rRNA gene have identified ‘Candidatus Phytoplasma luffae’ belonging to group 16SrVIII in all three crops with highest similarity (98.04%, 99.51%, and 99.25%) to the loofah phytoplasma reference strain from Taiwan. This is the first report of detecting the same species of ‘Ca. Phytoplasma’ in three different genera of plants from Laguna located in Luzon island, the Philippines.

Genetic Variability in Fusarium oxysporum f. sp. vasinfectum Causing Damping-off of Cotton (Gossypium barbadense L.) Seedlings
Reda Helmy Sammour, Salah Abdel Moemen, and Eman Elagamy

Received: 06 October 2020/ Revised: 21 February 2021/ Accepted: 09 March 2021

The genetic variability of Fusarium oxysporum f. sp. vasinfectum isolates from Gossypium barbadense L. seedlings were assessed using pathogenicity, mycelial compatibility and RAPD analyses. The results showed that the disease incidence percentages and compatibility percentages considerably varied, extending from 33.2 to 86.6 % and 6 to 60 %, respectively in North Egypt and from 33.3 to 66.6 % and 0.0 to 20% and in South Egypt. They also showed that the isolates ISO-8 and ISO-19 had the lowest disease incidence (33.2%) as compared with isolate ISO-5 (86.6%). They also showed that the mycelial compatibility had a reversible relationship with disease incidence percentage. Cluster analyses based on either mycelial compatibility data or RAPD analysis separated the isolates with the highest disease incidence percentages and the isolates with the lowest disease incidence percentages in two separate groups. They also clustered the isolates with the highest disease incidence percentages in more than one cluster confirming their evolution from multi-gene genealogies. Moreover, they showed that the obtained mycelial compatibility groups (MCGs) and the loci generated by RAPD primers were partly associated, indicating that some (MCGs) were clonally derived. The wide genetic variability in the isolates of F. oxysporum f.sp. vasinfectum should be taken in consderation in desinging effective strategies to control the pathogen to avoid deterioration in Gossypium barbadense L. production.

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