Genetic variations among the isolates of Bipolaris Maydis based on phenotypic and molecular markers

Maydis leaf blight, caused by Bipolaris maydis, is an important disease of maize crop in Khyber Pakhtunkhwa (KP) Pakistan. Fifteen isolates of the pathogen, collected across KP, were studied for variability based on phenotypic and molecular markers. Significant variability among the isolates was observed when assessed using phenotypic traits such as radial growth, spore concentration, fungicide sensitivity and virulence. The isolates were classified into six culture groups based on colour, texture and margins of the colony. Conidial morphology was also variable. These were either straight or slightly curved and light to dark brown in colour. Fungicide test showed significant variation in the degree of sensitivity against Carbendazim. Isolate Bm8 exhibited maximum radial growth on carbendazim spiked plates. Conversely, isolate Bm15 showed the lowest radial growth. Variations in virulence pattern of the isolates were evident when a susceptible maize variety Azam was inoculated with spores of B. maydis. Genetic variability amongst the isolates was also estimated by RAPD as well as sequencing of ITS region. The RAPD dendrogram grouped all the isolates into two major clusters. Average genetic distance ranged from 0.6% to 100%, indicating a diverse genetic gap among the isolates. Maximum genetic distance was found between isolates Bm9 and Bm10 as well as Bm2 and Bm8. Conversely, isolates Bm13 and Bm15 were at minimum genetic distance. Phylogenetic dendrogram based on sequencing of ITS region grouped all the isolates into a single major cluster. The clusters in both the dendrogram neither correlate to the geographical distribution nor to the morphological characteristics.

A study of agrometeorological parameters for the Kharif maize at Anand (Gujarat)

A study was conducted on the behaviour of evaporation, evapotranspiration and potential evapotranspiration in different phenological phases, during the years 1989, 1990 and 1991 for Kharif Maize crop at Anand (Gujarat). It has been noticed that evapotranspiration and potential evapotranspiration attained maximum values in grain phase. In harvesting phase relative evapotranspiration and crop coefficient had lowest values. The seasonal crop coefficient was obtained 0.84. An attempt has been made in this paper to develop the regression models to estimate potential evapotranspiration and relative evapotranspiration.

Assessment of Acacia dealbata as green manure and weed control for maize crop

Acacia dealbata Link is one of the main invasive species in southwestern Europe and a resource with potential value for agriculture. Our objective was to assess the value of A. dealbata vegetative aerial biomass used as green manure and as a tool for weed control in maize crops through three sequential experiments. In 2017, an experiment was carried out with acacia green manure vs inorganic fertilization of pots sown with a field corn and a sweet corn hybrid with strong and weak nutrient demand, respectively. Nutrients were not released from acacia green manure at an appropriate timing, and maize suffered nutrient deficit. In 2018, a pot experiment was made outdoors incorporating acacia green manure at different times before maize sowing, and we found that a 4-month period was required for maximum nutrient release from acacia green manure. In 2019, an early and a late-field experiments were performed by incorporating acacia green manure 4 months before maize sowing. Physiological and agronomic data were recorded in maize, along with soil data, for all years, and weed data the last year. Altogether, most effects and interactions between genotype or environment and fertilization treatment were not significant, and some deficiencies caused by acacia green manure fertilization depend on genotype and environment. Incorporation of acacia green manure 4 months before maize sowing partially controlled weeds and replaced inorganic fertilization. However, deficiencies should be corrected with additional weed control practices and fertilization treatments, according to the nutrient demand of the crop and the soil environment.

Comparative effect of fertilization on cocoyam and component crops on Cocoyam-based intercropping systems in Uyo, Southeastern Nigeria

Field experiment was conducted at University of Uyo Teaching, research farm during the 2018 and 2019 cropping seasons to assess the effect of fertilization on cocoyam-based intercropping systems. The experiment was laid out in a randomized complete block design with three replications. Treatments were six fertilizers rates - 0kg/ha, NPK200kg/ha, NPK400kg/ha, PM2.5t/ha, PM5.0t/ha, Mixture (NPK200kg/ha + PM2.5t/ha) and six crop mixtures - Sole Cocoyam, Sole Melon, Sole Maize, Cocoyam + Maize, Cocoyam + Melon and Cocoyam + Melon + Maize). Result analysed with analysis of variance revealed PM2.5t/ha, NPK400kg/ha and Mixture (NPK200kg/ha + PM2.5t/ha) gave higher plant height, leaf area, stem girth in sole cocoyam, maize and melon respectively. PM2.5t/ha favoured leaf area, stem girths of cocoyam, maize with cocoyam + maize, cocoyam + melon and cocoyam + melon + maize crop mixtures. PM5.0t/ha gave higher values of corm, cormels, cormels weight, cormels number and cormels length in both sole cocoyam and mixtures (cocoyam + melon, cocoyam + maize, cocoyam + melon + maize) in both seasons respectively. PM2.5t/ha gave higher values of maize grain yield with cocoyam + maize, cocoyam + melon + maize crop mixtures. PM5.0t/ha and NPK400kg/ha gave higher melon seed values with cocoyam + melon and cocoyam + Melon + maize. Conclusively, it is recommended that application of organic fertilizer promotes higher yields and yield components in both sole and crop mixtures of cocoyam and maize respectively.

Identification and crop damage assessment of indian crested porcupine (Hystrix indica) in selected zones of Abbottabad, Pakistan

Indian crested porcupine is the largest rodent pest that damages a wide variety of crops, vegetables, and tree species which ultimately causes huge economic loss in Pakistan, which is an agricultural country. It prefers to live in hilly terrain but common in temperate and tropical forests, shrublands, and grasslands. This study focused on the identification and assessment of crops damaged along with the main precautionary measures used by the local farmers. The data was collected from twenty-four villages of two union councils i.e. Chamhad and Slahad of district Abbottabad. Two types of data (primary and secondary) were collected from the study area. Primary data was collected for identification and estimation calculation of total crop damaged through direct field observation by taking random quadrates in each village of the study area. The damage in the crop was assessed by randomly selecting a quadrate of 1x1 m2 for the wheat, pearl millet, and Sorghum fields. While 4x4 m2 quadrates were taken for maize and vegetables. At least three quadrate samples were taken from each field including one quadrate taken from the center of the field area. In union council Chamhad, damage to maize (11.31%) and wheat (0.73%) by the Indian crested porcupine while in union council Salhad, damage of maize (6.95%) and wheat (1.6%) was observed. In the entire study area, overall damage to maize crop (8.01%) and wheat (0.88%) was calculated. Based on information obtained from the farmers, the Indian porcupine inflicted damage to potato, tomato, cauliflower, chili pepper, turnip, radish, pea, and onion, etc. Secondary data obtained through a questionnaire survey to explore the human porcupine conflict and precautionary measures used by the farmers and landowners. Open and close-ended questionnaires (159) highlighted the presence of Indian crested porcupine in the study area and 96% of the respondents have seen porcupine directly. Many types of precautionary measures were used by the farmers such as fencing, night stay, night firing, and dogs to decrease the crop damage, respondents (63.91%) use guns for hunting. however, due to the largely agricultural area and nocturnal behavior of Indian crested porcupine majority of the respondents (51.57%) did not use any precautionary measure. Biological control of Indian porcupine is recommended in the study area. Farmers should be encouraged and provide incentives and killing through current should be banned while proper hunting license should be issued to overcome overhunting. Scientific studies are required to control the reproduction of porcupine specifically in the more damaged areas.

Fungivory: a new and complex ecological function of Doru luteipes (Scudder) (Dermaptera: Forficulidae)

We report the discovery that the earwig predator Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) feed on Puccinia polysora Underw uredospore, the causal agent of Southern Rust of Corn (SRC), which is a primary disease affecting the maize crop in Brazil. We performed experiments in laboratory and greenhouse to test the effect of D. luteipes (1st/2nd and 3rd/4th instars, and adults) fungivory on the P. polysora uredospore concentration. All trials showed a significant reduction of the initial concentration of uredospore. There was a reduction in uredospore concentration with increase in number of D. luteipes feeding on them. We also tested the uredospore consumption by quantifying its percentage in the feces of D. luteipes. Nymphs of the 2nd, 4th instar and adults fed 88%, 85%, and 83.8% of the uredospore, respectively. For nymphs of the 3rd instar, the percentage of uredospore consumption (75.6%) was statistically significant compared with the other groups. In greenhouse experiment, at twenty-eight days after plant inoculation with 9.9 x 104 uredospores, the percentage of uredospore consumption was 81.7%. Our results confirmed the fungivory of D. luteipes on P. polysora uredospore. This is the first report of D. luteipes fungivory, which may play an important role in the biological control of P. polysora in corn.

THE EVAPOTRANSPIRATIVE DEMAND AND WATER USE EFFICIENCY OF MAIZE CROP (ZEA MAYS L.) IN THE SEMI-ARID TRACT OF INDIA

Mai ze is an Impo rta nt component o f th e d ry lau d fanning system o f India. In th e present study.d ata fur five years' period for three 51ation s. viz.. New Delhi. Rajendran agar an d Bellary in th e dry farm ing tr act ofInd ia have been iuili zed to und erstand evapotra nspira tive deman d of the crop in relat ion to pan-evaporat ion , andsolar rad iation. Biomet ric cha racte ristic. e.g.. heil:ht ofthe pla nt has also been analysed \'U-U-I';S meteorological facton.' V,lIer use efficie ncy of maul," has also been workedout nnd discu ssed . Th e analysis indica ted th ai th e maize plant uses maximum water during the flowering stage. Th e ETJEP rati ogradu ally in creases fmm germination aua ining a maximum value 8 to 10we eks after sowing.Th is ratio is found 10 besignilican tl)' correlated with the plan t height . The ETIR, curve was found 10 follow a sigm oid patt ern reac hingmaximum during flowering stage. Th e water use efficiency of maize crop vari es ove r wide margins in limeand space.

Monitoring of damage and distribution of invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on maize crop in Karo, North Sumatera, Indonesia

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest from America and has recently become an important pest in Indonesia. In their new environment, these pests have very high migratory and adaptive skills, as well as aggressive feeding habits. The aim of this research was to monitor the distribution, percentage of attacks, and damage caused by S. frugiperda on maize fields in the Karo District of North Sumatra Province. The study was conducted using a survey method at various altitudes and the sample unit was determined using the diagonal method. Each sample unit has a size of 2 × 2 m2. The age of maize crop used as the sample is 2-4; 5-6; 7-8; 9-10; and 11 weeks after planting (wap). Symptoms of attack, number of larvae population, and percentage of FAW attack were observed directly on plants. The results showed that FAW spread evenly at various altitudes, with the highest population at an altitude of 500-1,000 m.a.s.l at the age of 2-4 wap with a larval population density of 14.20 individual/unit sample. The highest percentage of attack was found at an altitude of 500-1,000 m.a.s.l, namely 82% at 2-4 wap. The highest attack on leaves occurred at an altitude of 500-1,000 m.a.s.l (70.6%) at the age of 2-4 wap.