Phenological traits of red amaranth varieties with a high content of amaranthine cultivated in open fields of Moscow region

The article focuses on phenological features of amaranth varieties grown in open fields as a reaction to variability of weather conditions in the Moscow region. Amaranthine is one of the promising compounds found in red-colored amaranths. It refers to a class of betalain pigments. The study revealed growth stages defined by the highest content of amarantine per plant and analyzed accumulation of the pigment in amaranth leaves and inflorescences. Phenological observations of introduced plant species under new conditions are important and determine their resistance to adverse environmental factors, ability to produce high quality fruits and seeds, and potential for cultivation. During the introduction of new amaranth varieties, the most adapted forms were selected for the conditions of the Non-Chernozem zone of the Russian Federation in 2013-2016. The studied Russian and Ecuador varieties were divided into 4 groups depending on the growth period (from germination to seed maturity). Analysis of phenological traits of plants confirmed that period of amaranth development did not depend on the variety, except the fourth stage of late-ripening cultivars - Don Pedro and Eku 17020, dependent on weather conditions. Being dependent on weather conditions, the vegetative growth period turned to be the most stable. Late cv. Eku 17020 did not form mature seeds in open ground conditions, which is explained by its origin (Ecuador). In the present study we identified growth stages when plant raw materials had the highest dye content in red-leaved amaranth varieties (Valentina, Don Pedro and Fakel). We also considered the perspective of cultivation of green-leaved varieties with red inflorescences - Pamyati Kovasa and Eku-17020 - as sources of biologically valuable compounds in the Moscow region.

Грибковые патогены в листьях нижнего яруса сортов томата Mary Gratefully и Tomiș

Pathogenic fungi are the cause of various diseases of crops. Phytopathogens infect seeds as well as the host-plants in the course of the whole duration of their ontogenesis. Plants are infected when grown in greenhouses or in open fields by a single causal agent or several pathogenic fungi. In current study, a nested PCR protocol was applied for identification of tomatoes’ infection. An infestation with Alternaria spp. and Myrothecium roridum in the lowest leaves on the stem was stated using molecular diagnostics. The ‘Tomis’ and ‘Mary Gratefully’ tomato cultivars were used in current study. Alternaria spp. was iden-tified in each of the samples. The pathogen’s species was defined. Myrothecium roridum infested 10 sam-ples of the ‘Tomis’ genotype and 11 samples of the ‘Mary Gratefully’ genotype of the 12 samples.

Impact of Rainwater Recharging on the Yield of Borewells at the GKVK Campus, Bengaluru

The study was conducted to analyze the effect of recharging the borewells through rooftop rainwater and runoff water harvesting from open fields during the year 2020-21. Nine borewells were chosen for the study, with seven borewells using various recharge strategies and two borewells serving as controls. The yield from these borewells is measured at 15-day intervals on a regular basis. During the Kharif season of 2020-21, three borewells (BW1, BW3, and BW5) measured a constant discharge of 0.3 lps, 0.4 lps and 3.2 lps respectively, four borewells (BW2, BW4, BW6, and BW7) measured a rise in discharge from 2.4-2.8 lps, 2.3-2.4 lps, 2.2-2.6 lps, and 1.6-2 lps, respectively, and two borewells (BW 8 and BW9) without any recharge technique measured a drop in discharge from 3-2lps and 2.4-2lps, respectively. During the subsequent Rabi season five borewells (BW1, BW2, BW3, BW4 and BW6) showed a constant discharge of 0.3lps, 2.8lps, 0.4lps, 2.4lps and 2.6lps respectively, two borewells (BW5 and BW7) continued to have an increased discharge 3.2-3.4lps and 1.8-2 lps, respectively and the two control borewells (BW 8 and BW9) continued to show a decrease in the discharge from 2-1.8lps and 1.9-1.8lps, respectively. As a result, the procedure of recharging of borewells through rainwater had a significant impact on borewell yield. The yield of recharged borewell had shown an increase in discharge or had a constant discharge during the Rabi season.

Distribution, abundance and natural enemies of the invasive tomato leafminer, Tuta absoluta (Meyrick) in Kenya

Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± 0.45, respectively. Trap captures in terms of moth/trap/day were linearly and positively related to leaf infestations in open fields (R2 = 0.81) and greenhouses (R2 = 0.61). Highest fruits’ infestation and damage were 60.00 and 59.61%, respectively, while the highest number of mines per fruit was 7.50 ± 0.50. Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus (Rambur) were identified as predators of T. absoluta larvae. Nine species of larval parasitoids were recovered from infested foliage, with a combined parasitism of 7.26 ± 0.65%. Hockeria species was the most dominant (31.25%) and accounted for 12.88 ± 1.47% parasitism. Two species of larval parasitoids, Hockeria and Necremnus were obtained from sentinel plants with an average parasitism of 1.13 ± 0.25. The overall abundance and parasitism rates of recovered natural enemies were low to effectively control the field populations of T. absoluta. These findings form the basis of researching and developing effective and sustainable management strategies for the pest.

Pesticide Residues on Tomatoes Grown and Consumed in Mwea Irrigation Scheme, Kirinyaga County, Kenya

The effects of pesticides on human health are of great concern worldwide despite their usefulness in agriculture. The aim of the study was to evaluate pesticide residues on tomatoes grown and consumed in Kirinyaga County in order to determine whether the levels fall within recommended MRLs. Reported increased use of unspecified pesticides and undocumented residue levels in tomatoes produced in the country justified the need to evaluate pesticide residues in tomatoes grown in the area and consumed locally. The study, which was conducted in Mwea Irrigation Scheme, Kirinyaga County, Kenya between July 2017 and July 2018 used analytical study design. Tomato samples of Rambo variety mainly grown in open fields and greenhouses in the Irrigation Scheme were purposively sampled from thirty-five sampling sites in open fields, greenhouses, markets and consumers. The samples were taken to Kenya Plant Health Inspectorate Services (KEPHIS) laboratory in Nairobi for analysis. Analysis was done using Quick Easy Cheap Effective Rugged and Safe (QuEChERS) multi-residue analytical method for Low-Fat products. Four pesticide residues detected on tomatoes above the recommended EU and Cordex MRLs were: malathion (0.0315±0.0032 mg/kg) in open fields, carbendazim (1.2341±0.1667 mg/kg) and thiamethoxam (0.3736±0.0358 mg/kg) from greenhouses and acephate (0.0321±0.0032 mg/kg) from the market. Pesticide residue levels of tomatoes from consumers were all significantly (p<0.001, p<0.01) below the EU and Cordex permitted MRLs. Occurrence of pesticide residues on tomatoes from production to consumption levels is of great concern to consumers because of the perceived long term negative health effects. Implementation, strengthening and enforcement of the food policy in the country will enhance frequent monitoring of pesticide residue levels in fresh produce consumed locally in Kenya.

Author Correction: Violet LED light enhances the recruitment of a thrip predator in open fields

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Helenium amarum (bitterweed).

Helenium amarum is an annual herbaceous plant native to North America. It is native to some states in America, but introduced in California, Connecticut, Maryland and Massachusetts. It has also been introduced in Queensland, Australia. H. amarum is potentially weedy in many of the areas in which it grows. It is an opportunistic colonizer that will quickly spread into areas when taller vegetation is removed, and has the potential to become abundant in open fields, roadsides and wastelands. It is poisonous to most mammals, and if eaten by cows will cause their milk to become bitter and unusable. Helenium amarum is classed as an invasive weed in the USA, where it has spread widely in its native range and now covers a substantial portion of the grazing land in Texas. In Queensland, Australia is is considered an environmental weed and subject to control efforts. It was reported as eradicated in 2002 but has since been identified as present in low numbers.