Presence of Late Blight of Potato in Uzbekistan and Measures to Combat It

The article discusses the development of a disease of cultivated plants, which was previously not typical for the conditions of Uzbekistan — late blight of potato. On the territory of the Tashkent region and the small educational economy of the Tashkent State Agrarian University in 2015–2020, the presence of late blight was noted on potato crops. The degree of development of the disease is 27.9–36.3%. A study was carried out on the use of new drugs: Antracol 70% and Banjo Forte. The best result in suppressing the disease was shown by the preparation Antracol 70% in the norm of application — 2.0 kg/ha, where 20 days after treatment the biological efficiency was 85.6%. The biological efficacy of Banjo Forte at a rate of 1.0 l/ha was 81.8% on the leaves, 84.1% on the shoots, and 1.5% and 1.0%, respectively, with the development of the disease.

The Automation of Hyperspectral Training Library Construction: A Case Study for Wheat and Potato Crops

The potential of hyperspectral measurements for early disease detection has been investigated by many experts over the last 5 years. One of the difficulties is obtaining enough data for training and building a hyperspectral training library. When the goal is to detect disease at a previsible stage, before the pathogen has manifested either its first symptoms or in the area surrounding the existing symptoms, it is impossible to objectively delineate the regions of interest containing the previsible pathogen growth from the areas without the pathogen growth. To overcome this, we propose an image labelling and segmentation algorithm that is able to (a) more objectively label the visible symptoms for the construction of a training library and (b) extend this labelling to the pre-visible symptoms. This algorithm is used to create hyperspectral training libraries for late blight disease (Phytophthora infestans) in potatoes and two types of leaf rust (Puccinia triticina and Puccinia striiformis) in wheat. The model training accuracies were compared between the automatic labelling algorithm and the classic visual delineation of regions of interest using a logistic regression machine learning approach. The modelling accuracies of the automatically labelled datasets were higher than those of the manually labelled ones for both potatoes and wheat, at 98.80% for P. infestans in potato, 97.69% for P. striiformis in soft wheat, and 96.66% for P. triticina in durum wheat.

Gross Primary Production of Rainfed and Irrigated Potato (Solanum tuberosum L.) in the Colombian Andean Region Using Eddy Covariance Technique

Potato farming is relevant for global carbon balances and greenhouse emissions, of which gross primary productivity (GPP) is one of the main drivers. In this study, the net carbon ecosystem exchange (NEE) was measured using the Eddy Covariance (EC) method in two potato crops, one of them with an irrigation system, the other under rainfed conditions. Accurate NEE partition into GPP and ecosystem respiration (RECO) was carried out by fitting a light response curve. Direct measurements of dry weight and leaf area were performed from sowing to the end of canopy life cycle and tuber bulking. Agricultural drought in the rainfed crop resulted in limited GPP rate, low leaf area index (LAI), and low canopy carbon assimilation response to the photosynthetically active radiation (PAR). Hence, in this crop, there was lower efficiency in tuber biomass gain and NEE sum indicated net carbon emissions to atmosphere (NEE = 154.7 g C m−2 ± 30.21). In contrast, the irrigated crop showed higher GPP rate and acted as a carbon sink (NEE = −366.6 g C m−2 ± 50.30). Our results show, the environmental and productive benefits of potato crops grown under optimal water supply.

CONSTRAINTS FACED DURING THE PRODUCTION AND MARKETING OF CABBAGE AND POTATO CROPS: A COMPARATIVE STUDY OF MANIPUR AND NAGALAND STATES OF INDIA

The present study was carried out by purposively simple stratified random sampling technique to select 300 respondents from both the states of Manipur and Nagaland, while to highlight the constraint faced by the growers during the production and marketing of cabbage and potato crops with Garrett Ranking Technique. For the production viz.; seed, labour, manures and fertilizers, irrigation, PPCs and other issues like animals, pests and diseases, have hampered of the potato and cabbage in the selected areas. While for marketing high price of the seed, not available in time, inferior quality of seed, low reliability of the seed, high wage rates of labour, skill & unskilled labour not available in time, irrigation facility not available, perennial sources are not available and irrigation facility not reliable etc; While for the market related issues, grading by hand & mechanical means, lack of knowledge regarding packaging, packing materials, high cost of transportation, lack of market infrastructures, unauthorized & illegal tax collections, use of improper scales in weighing, lack of support prices, lack of reliable & timely availability of market information and distant market along with the lack of cooperation among the producers and frequent ban & social boycott are some of the problems and constraints encountered by the entire producers and market intermediaries in the region.

The results of catching winged aphids with water traps on potato plantings in the southern part of the Arkhangelsk region

Dynamics of the number and species composition of aphids were studied on seed potatoes using yellow water traps in the southern part of the Arkhangelsk region in 2018-2019. 12 species of winged aphids (165 insects) were identified in 2018, and 16 species (115 insects) - in 2019. The following types dominated: black bean aphid A. fabae Scop., bird cherry-oat aphid R. padi L., blackcurrant-sowthistle aphid H. lactucae L., glasshouse-potato aphid A. solani Kalt. The share of aphids as direct and indirect vectors of viral diseases was 91 % of the total number in 2018, and 79.1 % in 2019. The pest population of potato plants depended directly on weather conditions of the growing season. The sum of the average daily temperatures during the period of catching aphids was 1273.3 C in 2018, and 983.3 C - in 2019. During the experimental period, 131.6 mm of precipitation fell in 2018, and 280.4 mm - in 2019. Due to the constant presence of aphids on seed potato crops, annual monitoring of pest population and, in case of necessity, protective measures are required.

Effective control of two genotypes of Phytophthora infestans in the field by three oxathiapiprolin fungicidal mixtures

In two field experiments, performed in 2020 and 2021, potato Nicola plants were sprayed once with three (Exp. 1) or two (Exp. 2) doses of Zorvec Vinabel (oxathiapiprolin+ zoxamide = ZZ), Zorvec Encantia (oxathiapiprolin+ famoxadone = ZF), Zorvec Endavia (oxathiapiprolin+ benthiavalicarb = ZE), Infinito (= INF) or Mefenoxam (= MFX) and thereafter inoculated with genotype 23A1 or 36A2 of Phytophthora infestans. Disease development was recorded at periodic intervals for a month. In both experiments, Zorvec mixtures were significantly more effective in suppressing the disease than INF or MFX. They delayed the onset of the disease and its progress, regardless the genotype used for inoculation. Among the three Zorvec mixtures, ZZ was least effective and ZE most effective. Sensitivity monitoring assays revealed zero mutants of P. infestans resistant to oxathiapiprolin. The data confirmed good efficacy of Zorvec mixtures, especially ZE, in field-grown potato crops as evident by the very effective control of late blight for one month.