Intercropping Systems in Wheat (Triticum sativum L.) for Insect Pests and Disease Management – A Review

Cereal crop wheat, Triticum sativum L., is an important food and feed crop that is grown all over the world. There is a complementary relationship between legumes and cereals for nitrogen resources, it was found that intercropped legumes acquire a higher amount of atmospheric nitrogen in comparison to legumes grown as an individual crop. Furthermore, both wheat and pulse intercropping give benefits in terms of minimizing pests and diseases. Intercropping not only restricts onset of pest species but also crop combinations conserves beneficial insects that can preserve the damaging pest population below the threshold level. In the current study, numerous instances were provided that show successful control of various insect pests when wheat was intercropped with mustard, Linseed, barley, mung bean, canola, and other crops. Wheat intercropping with other crops can be used as part of an integrated pest management strategy to reduce pest incidence while also increasing the number of beneficial organisms.

The diversity of chili pepper volatile compounds and its relationship to insect pests

Selection activities in plant breeding can be carried out only if there is variation in the plant’s genetic materials. Plant volatile compounds are media for interaction between plants and insects, making them potential to be used as a selection parameter in resistant plant breeding programs against insect pests. This study aimed to determine the diversity of chili pepper (Capsicum spp.) volatile compounds and to explain its relationship to the main insect pests of chili pepper. The research was carried out at IVEGRI’s research station in Lembang, West Java, Indonesia from March to September 2020. The treatment involved 34 chili pepper varieties. The observation parameters included profiles of volatile compounds measured using GC-MS and incidence of main insect pests (thrips, worms, and fruit fly). The results showed that 87 volatile compounds detected, eight of them, i.e. 3,6-Nonadien-1-ol, (E, Z)-,β-Ocimene, trans-β-Ocimene, 3-Allylcyclohexene, 2,4,6-Octatriene, 3,4-dimethyl-, Neo-allo-ocimene, 1-Octanol and 2-Methylanisole showed a high level of diversity among the chili pepper varieties tested. The results of a simple correlation test showed positive and negative correlations between eight volatile compounds and pest incidence, with a range from -6.80 to 0.87. The relationship between these volatiles compounds and pest incidence will be subject to a further discussion.

Integrated Pest Management for Cucurbits in Cucumber (Cucumis sativus L.)

The vegetables belonging to family cucurbitaceae are known as cucurbits. These vegetables are attacked by various insect pests right from seeding to harvest. A lot of money, time, and natural resources are invested to cultivate these vegetables. Sustainable pest management practices can save this investment by avoiding losses. Successful cultivation of cucurbits especially cucumber requires an effective and economical control of insect pests. Commercial vegetable growers must produce quality vegetables that are attractive and safe to the consumer at a minimum cost. Insect pest infestations in cucurbits cause heavy economic losses to farmers through reduction in yield, increased cost of production and lowered quality of produce. Effective and economic and sustainable pest management requires the use of cultural, mechanical, biological, and chemical methods. The integration of these different methods is necessary for achieving good management of pests. In case of cucurbits especially for cucumber pest management can be achieved only by a long-term assurance to integrated pest management practices (IPM). IPM involves the strategic use of resistant varieties, monitoring of pest incidence, cultural methods, mechanical removal of pest, biological control, and need based use of selective pesticides. Integrated pest management (IPM) is the alternative to insecticide and facilitates sustainable environment management.

UV-B light and its application potential to reduce disease and pest incidence in crops

Ultraviolet-B radiation (280–315 nm), perceived by the plant photoreceptor UVR8, is a key environmental signal that influences plant growth and development and can reduce disease and pest incidence. The positive effect of UV-B on disease resistance and incidence in various plant species supports the implementation of supplemental UV-B radiation in sustainable crop production. However, despite many studies focusing on UV-B light, there is no consensus on the best mode of application. This review aims to analyze, evaluate, and organize the different application strategies of UV-B radiation in crop production with a focus on disease resistance. We summarize the physiological effects of UV-B light on plants and discuss how plants perceive and transduce UV-B light by the UVR8 photoreceptor as well as how this perception alters plant specialized metabolite production. Next, we bring together conclusions of various studies with respect to different UV-B application methods to improve plant resistance. In general, supplemental UV-B light has a positive effect on disease resistance in many plant–pathogen combinations, mainly through the induction of the production of specialized metabolites. However, many variables (UV-B light source, plant species, dose and intensity, timing during the day, duration, background light, etc.) make it difficult to compare and draw general conclusions. We compiled the information of recent studies on UV-B light applications, including e.g., details on the UV-B light source, experimental set-up, calculated UV-B light dose, intensity, and duration. This review provides practical insights and facilitates future research on UV-B radiation as a promising tool to reduce disease and pest incidence.

Early Morphological Growth Response and Incidence of Key Pests Under Two Spacing Regimes of Coffea canephora

Coffea canephora has non-limiting but unexploited yield and quality potential when compared with C. arabica. Coffee tree density optimization can improve fortunes of smallholder farmers. An attractive example is that high productive countries where high plant densities do increase area yield but across boardrecommendations are illogical especially with variety and agroecological variations. We aimed to compare two spacing regimes for growth response and pest incidence using Kituza Robusta clone. Randomized complete block designs with three replications and eight plants per plot were established at four agroecologically diverseon-farm locations. Eleven plant growth variables were measured. In addition incidences of five key pests were assessed. Data was collected on a 3-month interval starting from 12 up to 21 months after planting. Highly significant differences between spacing regimes (p<0.01) were obtained for majority of variables. Mean growth response was generally higher under 3 m x 1 m (high density) than 3 m x 3 m (low density) particularly with stem girth, plant height, length of longest primary branch, and leaf blade length. Conversely, pest incidence of black coffee twig borer, leaf eating beetles, leaf miners, and tailed caterpillars, except skeletonizers was higher under high than low plant densities. The findings provide aguide on implications of high plant densities on growth robustness which is translatable into yield potential; amidst a pest prevalence dilemma in studied type of C. canephora.

Management Practices for Whitefly and Thrips in Mungbean

This experiment was conducted at the central farm of Sher-e-Bangla Agricultural University, [23.740 N latitude and 90.350 E longitude] Sher-e-Bangla Nagar, Dhaka, Bangladesh, during the period of March to May, 2014 to study the Whitefly and Thrips pest incidence in mungbean and their management practices BARI Mung-5 was used as the test crop for this experiment. The experiment consists of the following treatments: T1: Nitro 505EC (Chloropyrifos+Cypermethrin) @ 2 ml/L of water at 10 days interval; T2: Casper 5 SG (Emamectin Benzoate) @ 2gm/L; T3: Voliam Flexi (Thiamethoxam+Chlorantraniliprole) @ 0.25 ml/L; T4: Tapnor 40 EC (Dimethoate) @ 2.0 ml/L; T5: Allion 2.5 EC (Lamda-Cyhalothrin) @; T6: Admire 200SL (Imidachorpid) @ 0.25 ml/Land T7: Control. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The lowest number of whitefly infestation per plant in the vegetative stage (4.18) and reproductive stage (2.13) was recorded from T6 treatment, whereas the highest (14.44) and (8.10) was recorded from T7 treatment in respective stage. Thrips infestation was higher (6.32) per 5 flower was recorded from T7 treatment whereas lower infestation (1.88) per 10 flower was recorded from T6. The lowest yield per hectare (1.27 ton) was found in T7 and lowest benefit cost ratio (4.16) was found in T5 whereas highest yield per hectare (1.53 ton) was found in T6 and highest benefit cost ratio (12.81) was found in T3 treatment. Among the management practices for controlling whitefly and thrips of mungbean Admire 200SL @ 0.25 ml/L of water was more effective which was followed by Voliam Flexi (Thiamethoxam+Chlorantraniliprole) @ 0.25 ml/L of water Farmers should use Admire 200SL(Imidachorpid) @ 0.25 ml/L of water at 10 days interval for controlling whitefly and thrips in mungbean.

Influence of Pre-Harvest Bagging on the Incidence of Aulacaspis tubercularis Newstead (Hemiptera: Diaspididae) and Fruit Quality in Mango

Aulacaspis tubercularis Newstead (Hemiptera: Diaspididae) is the main pest of mango, Mangifera indica L., in Spain, causing significant economic losses by aesthetic damage that reduce the commercial value of fruit. Bagging fruit with two commercial bags (a yellow satin paper and a white muslin cloth bag) was evaluated for control of A. tubercularis in two organic mango orchards during the 2020 cropping season in pursuit of the development of a mango IPM program to produce pest-free and residue-free fruits. Results from fruit damage evaluations at harvest showed that bagging significantly reduced pest incidence and fruit damage compared with non-bagged plots. Of the two bags evaluated, white muslin cloth bag provided higher levels of fruit protection from A. tubercularis damage, reducing the non-commercial fruit percentage by up to 93.42%. Fruit quality assessment indicated that weight and size of bagged fruit were significantly higher than the non-bagged. Paper-bagged mangoes showed higher whiteness and yellowness compared to the other treatments. Soluble solids content (ºBrix) was higher in paper-bagged fruit than all other treatment plots. The results from this study indicate that pre-harvest fruit bagging is effective at controlling A. tubercularis and should be integrated into an IPM program for Spanish mango production.

High Robusta coffee plant density is associated with better yield potential at mixed responses for growth robustness, pests and diseases: which way for a farmer?

Plant density in Robusta coffee is an unresolved issue in low volume producing countries especially when compared with leading producers. In this study, we aimed to compare the response of Robusta coffee to pest incidence, disease severity, growth and yield potential in two contrasting spacing regimes. Two spacing regimes of 3mx3m and 3mx1m were evaluated for selected parameters in a randomized complete block design with three replications. There was a highly significant difference in pest incidence between the spacing regimes (p<0.01) for all the pests except scales (p=0.126). The black coffee trig borer incidence was higher under close spacing of 3mx1m than for 3mx3m with a mean difference of 13.2%. There was no significant association between spacing regime and leaf rust disease incidence while the association was significant for red blister disease (χ2=33.56, df=1, p<0.001). Significant difference in growth response between spacing regimes (p<0.05) were also obtained for change in canopy height (dCAH), number of primaries, number of stems and leaf size. For instance, dCAH was higher under 3mx1m spacing than for 3mx3m spacing. A significant difference in yield potential existed between the spacing regimes (p<0.05) for average yield per tree and average yield per hectare (aYH). Close spacing produced a higher aYH (5.82 t cc/ha) than wide spacing (4.80 t cc/ha). Whereas yield potential is high at high tree densities, associated prevalence of biotic constraints calls for supportive stress management package for farmers.

Effect of Different Colored Polythene Mulches and Net House on Insect Incidence and Yield of Brinjal in Rampur, Chitwan

Field experiment was conducted in single factor randomized complete block designed to evaluate effect of different color polythene mulch and net house on insect pest incidence of brinjal in chitwan, nepal during october 2016 to may 2017. Five different treatment were selected with four replications, included net house with black polythene mulch, black polythene mulch only, reflective polythene mulch only and black polythene mulch with emamectin benzoate 5%sg spray and control (no mulch+ no net + no pesticide spray) . The result revealed that the net house totally restricts the brinjal shoot and fruit borer whereas black polythene mulch with emamectin benzoate spray plot reduced brinjal shoot and fruit borer larvae upto 70.58%. Total marketable yield was found highest in the black polythene mulch with emamectin benzoate spray plot (49.17 mt /ha) followed by black polythene mulch only (38.59 mt/ha) and lowest in control plot (28.53 mt/ha). Damaged fruit percentage by brinjal fruit and shoot borer was highest in the control (35.68%) followed by black polythene mulch (28.10%), reflective polythene mulch (19.02%) and lowest in net house with black polythene mulch (0%). The damaged weight inside the net house with black polythene mulch and black mulch with pesticide were significantly different whereas the damaged weight in other treatments similar which proved that there was no effect of mulch on brinjal shoot and fruit borer. The B:C ratio was the highest (3.34:1) in the black polythene mulch with emamectin benzoate spray plot while the lowest in net with black polythene mulch (1.68:1). Although the B:C ratio was lower in the net with black polythene mulch due to the low yield in the winter season. Creation of suitable soil environment by black polythene mulch and being biologically originated, having minimum residual effect and short half-life of emamectin benzoate, black polythene mulch with emamectin benzoate can be used for the eco-friendly management of brinjal shoot and fruit borer.