Fruit rot disease (FRD) of arecanut, caused by Phytophthora meadii, is an important fruit disease of this palm tree that resulted in huge economic losses to the growers in India. In recent years, the control of this disease has become a prime factor in the management of arecanut plantations. Though prophylactic sprayings of Bordeaux mixture (1%) along with other older fungicides are useful in reducing the disease severity. Hence, there is an urgent need for new generation molecules to combat FRD under field conditions. The present investigation was aimed at evaluating newer oomycete-specific fungicides in in-vitro on different life stages of Phytophthora and in-vivo through a Bunch Spraying System (BSS) from ground level. The pathogen was isolated, identified, and characterized from varied regions and one virulent isolate from each region was used. Out of the 11 fungicides tested, EC₅₀ for mycelial inhibition among isolates was lowest in Famoxadone + Cymoxanil. Similarly, the lowest EC₅₀ for sporangial production was recorded in Iprovalicarb + Propineb, Famoxadone + Cymoxanil, and Kresoxymethyl ranging from 210.70 to 517.87 mg mL^_1. The most effective fungicide for inhibition of zoospore release was Dimethomorph + Mancozeb which ranged from 406.81 to 565.80 mg mL^_1. Bunch spraying of fungicides such as Bordeaux mixture (1%), mandipropamid (0.5%), fosetyl-Al (0.3%), and a combination of metalaxyl-mancozeb (0.2%) from ground level had a significant (P < 0.05) effect against FRD. These fungicides were found most effective in reducing the disease up to an extent of 65–70% and which in turn increased the dry nut yield by 75–95% when applied twice compared to untreated control. However, a semi-systemic fungicide mandipropamid could be a potential alternative to the Bordeaux mixture for effective control of FRD under field conditions.

由Phytophthora meadii引起的槟榔果实腐烂病 (FRD)是这种棕榈树的一种重要果实病害，给印度种植者造成了巨大的经济损失。近年来，该病害的控制已成为槟榔种植园管理的主要因素。虽然预防性喷洒波尔多混合物 (1%) 以及其他较老的杀真菌剂有助于降低疾病的严重程度。因此，迫切需要新一代分子在野外条件下对抗 FRD。本研究的目的是在不同生命阶段的疫霉菌和体内评估新型卵菌特异性杀菌剂通过地面喷洒系统 (BSS)。从不同地区分离、鉴定和表征病原体，并使用来自每个地区的一种强毒分离株。在测试的 11 种杀真菌剂中，法莫沙酮 + 霜霉腈对分离株菌丝体抑制的 EC ₅₀最低。类似地， Iprovalicarb + Propineb、Famoxadone + Cymoxanil 和 Kresoxymethyl 记录的孢子囊产生的最低 EC _{50范围为 210.70 至 517.87 mg mL} ^_1。抑制游动孢子释放最有效的杀菌剂是烯酰吗啉+代森锰锌，浓度范围为 406.81 至 565.80 mg·mL ^_1. 波尔多液（1%）、杀虫胺（0.5%）、乙膦铝（0.3%）、甲霜灵代森锰锌（0.2%）等杀菌剂从地面堆喷效果显着（ P < 0.05）反对FRD。这些杀菌剂被发现最有效地减少了 65-70% 的疾病，并且与未处理的对照相比，施用两次后，干坚果产量增加了 75-95%。然而，半内吸性杀菌剂 mandipropamid 可能是波尔多混合物的潜在替代品，可在田间条件下有效控制 FRD。