Mwanauta Regina W, Ndakidemi Patrick A, Venkataramana Pavithravani B
School of Life Sciences and Bioengineering (LiSBE), Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
Tanzania Plant Health and Pesticides Authority (TPHPA), P.O BOX 3024, Arusha, Tanzania.
Heliyon. 2023 Mar 1;9(3):e14162. doi: 10.1016/j.heliyon.2023.e14162. eCollection 2023 Mar.
Worldwide, causes 75% of estimated economic loss in papaya farming, with an increase in production costs. The extract of plant essential oils (PEO) has the potential to control by degrading its wax coatings to death; however, it is less studied in the East African agroecosystem. Therefore, this study was conducted to evaluate the efficacy of four PEO from (neem, citrus, garlic, and castor) against at different concentrations (0.5%, 1%, and 1.5%) with and without 0.2% adjuvants separately as a biopesticide. The experiment was conducted in a completely randomized design with four replications per treatment concentration. The papaya seeds (Carina variety) were used in the experiment. After 3 weeks from transplanting, 50 specimens were inoculated in each plant. Before treatment application, insect abundance, leaf curling, yellowing, and soot mold were assessed. Then, 24 h, 48 h, and 72 h after biopesticide application, insect mortality was assessed. The results showed a significant difference ( = 0.001) for all assessment intervals in PEOs. However, for the PEOs in combination with the adjuvants, the results were significantly different ( = 0.001) only at 24 h. It was found that among the biopesticides, neem oil (1.5%) + isopropyl alcohol was highly effective (95.5%) after 72 h followed by (Imidacloprid (91%), citrus oil 1.5% (90.7%) and neem oil (1.5%) + paraffin oil (81.0%). But also, there were significant differences among treatments on leaf curling, yellowing, and soot mold reduction in papaya plants 21 days after spray. We conclude that neem oil (1.5%) + 0.2% isopropyl alcohol, neem oil (1.5%) + paraffin oil, and citrus oil (1.5%) significantly controlled . Thus, we recommend adopting these formulations for papaya farmers to control in their farms; however, simple formulations which can be easily accessed by smallholder farmers are essential.
在全球范围内，它导致番木瓜种植中估计75%的经济损失，且生产成本增加。植物精油提取物（PEO）有通过降解其蜡质涂层使其死亡来控制它的潜力；然而，在东非农业生态系统中对此研究较少。因此，本研究旨在评估四种来自印楝、柑橘、大蒜和蓖麻的植物精油在不同浓度（0.5%、1%和1.5%）下，分别添加和不添加0.2%助剂作为生物农药对其的防治效果。实验采用完全随机设计，每个处理浓度重复四次。实验使用了番木瓜种子（卡里纳品种）。移栽3周后，每株植物接种50个样本。在施用处理剂之前，评估昆虫数量、叶片卷曲、发黄和煤烟病情况。然后，在施用生物农药后24小时、48小时和72小时，评估昆虫死亡率。结果表明，在所有评估时间段内，植物精油之间存在显著差异（P = 0.001）。然而，对于添加助剂的植物精油，结果仅在24小时时存在显著差异（P = 0.001）。发现在生物农药中，印楝油（1.5%）+异丙醇在72小时后效果极佳（95.5%），其次是吡虫啉（91%）、柑橘油1.5%（90.7%）和印楝油（1.5%）+石蜡油（81.0%）。而且，喷雾21天后，番木瓜植株在叶片卷曲、发黄和煤烟病减轻方面的处理之间也存在显著差异。我们得出结论，印楝油（1.5%）+0.2%异丙醇、印楝油（1.5%）+石蜡油和柑橘油（1.5%）能显著防治它。因此，我们建议番木瓜种植户采用这些配方在其农场中防治它；然而，小农户能够轻易获取的简单配方至关重要。
