Sustainable management of two key pests of cabbage, Brassica oleracea var. capitata L. (Brassicaceae), using homemade extracts from garlic and hot pepper

Exploiting the Insecticidal Potential of the Invasive Siam Weed, Chromolaena odorata L. (Asteraceae) in the Management of the Major Pests of Cabbage and their Natural Enemies in Southern Ghana

“…The effectiveness of botanicals in the study was generally better as compared to the conventional insecticide in the control of aphid. This may be due the fact that, B. brassicae may gradually be developing resistance to the conventional insecticides Fening et al [12]. The performance of the plant extracts in reducing the population of B. brassicae indicates their usefulness in controlling insect pests when incorporated into Integrated Pest Management (IPM).…”

“…Fening et al [19] however, revealed that the use of plant extracts in IPM provides added advantage over the use of synthetic insecticide; as, they are not persistent in the environment, readily available, affordable and easily made. The findings on high number of multiple head formed on untreated plots as compared to treated plots indicated that, cabbage cannot be cultivated without making an attempt to control insect pests.…”

“…The DBM, for instance, has been one of the greatest threats to crucifer production in the tropics causing over 90% crop losses Charleston [10], if not managed. Farmers have limited control options and have therefore resorted to the use of synthetic insecticides which have led to insect pest resistance problems, toxic residues in cabbages posing high risks to humans, animals and the environment Ninsin, Amoako and Fening et al [8,11,12]. Botanicals, which are derived from plant products are reported to be effective against many insect pests and are considerably cheap and biodegradable when applied Amoabeng et al [13].…”

“…In Benin, the bushmint, Hyptis suaveolens (L.) Poit (Lamiales:Lamiaceae) extract has been used for the control of pink stalk borer, Sesamia calamistis H. (Lepidoptera: Noctuidae) on maize in the field. In Ghana, several botanicals such as neem seed extracts, Azadirachta indica; hot chilli pepper, Capsicum frutescens; garlic extract, Allium sativum; tobacco, Nicotiana tabacum; cassia plant, Cassia sophera; physic nut, Jatropha curcas; castor oil plant, Ricimus communis; basil, Ocimum gratissimum; goat weed, Ageratum conyzoides, Siam weed, Chromolaena odorata and Cinderella weed, Synedrella nodiflora, etc., have been used to protect foodstuffs such as vegetables in the field and stored grains against insect pest infestations Obeng-Ofori, Ankrah, Fening et al and Amoabeng et al [9,12,13].…”

“…They showed that although the 30 g/L C. odorata extract was effective in reducing pest populations, this concentration was however detrimental to natural enemies and nontargeted organisms in the field. Fening et al [19] have also cautioned that higher concentrations of botanicals could possibly have some detrimental effects on the natural enemy populations because their numbers reduce with increasing concentrations. Hence, the current research was conducted to optimize the concentrations of crude extract from Siam weed, C. odorata for effective control of the key pests of cabbage with minimal or no adverse effect on the natural enemies of these pests and other non-target organisms.…”