ABSTRACT
To increase watermelon (Citrullus lanatus) production, pesticides are now being used in higher quantities.Many pesticide combinations are harmful to seed production. This study was carried out to assess the effectsof pesticide combinations (i) α-cypermethrin + mancozeb (α-CpMa) and (ii) λ-cyhalothrin + acetamiprid +metalaxyl + copper oxide (λ-ChAMeC) on in vitro germination, viability, and storage of watermelon pollens.Pesticides were applied on field, on three varieties of watermelon plants (kaolack, F1-koloss, and F1-sugardragon), before and during blooming. The pollens were subjected to viability and germination tests directlyafter harvesting, or stored at +10°C or −20°C before testing. In vitro germination and viability of pollen werecarried out on modified Brewbaker and Kwack medium. Α CpMa and λ-ChAMeC inhibited pollen germinationin all the three varieties of watermelon. α-CpMa was the most harmful pesticide when applied during blooming,with up to 26.5% decrease in pollen germination. A decrease of pollen germination and viability was alsoobserved after 4 and 7 days of storage. Pollen from the variety kaolack showed a higher germination rate and,freezing at −20°C was the better storage condition. These results could help to scale up pollen sharing and seedproduction in watermelon breeding programs.
ABSTRACT
Bean is an annual legume, consumed by more than 500 million people worldwide. It is a base in their daily diet because of its high protein content (25-30%). In Cameroon, its culture has many problems, including the significant decline in fertility and soil acidity. This study aimed to evaluate the effect of organo-mineral fertilization on the bean production. The experimental design was a complete randomized block with two factors [varieties (NITU and DOR 701) and treatments (T0: control, T1: poultry manure and T2: NPK)] and three replications. The study was carried out at the second cropping season from August to November 2015 in Eloumden in the Mefou and Akono Division, Centre Region (Cameroon). The organo-mineral fertilization of two new varieties of beans was tested. The collar diameter, the number of leaves and the shoot length were evaluated weekly. At harvest, the nodulation and yield were evaluated. The results showed that treatment with poultry manure (T1) induced a very highly significant growth (P ˂ .001) of shoot length, as well as a significant increase in the number of pods (36 ± 5.91), the number of seeds (142 ± 88.07) and the biomass. The chemical fertilizer treatment (T2) induced the best nodulation (25.50 ± 0.87). The treatments did not influence the seed yield. However, the varietal effect was highly significant. DOR 701 had a higher seed yield (5.91 ± 1.03 t ha-1) than the NITU variety (4.19 ± 0.54 t ha-1). Poultry manure (T1) restores the minerals useful for the next crop. It is therefore recommended because of its best yield and its ability to protect the environment.