Kheloufi A.

Seed Germination and Seedling Establishment of Cherimoya (Annona Cherimola Mill.) at different Temperatures

A. Kheloufi, L.M. Mansouri, H. Khettache

ABSTRACT. Cherimoya (Annona cherimola Mill.) has an exceptional flavor and aroma, which makes it a fruit with great potential. However, little is known about its propagation by seeds. According to the scientific literature, the germination of cherimoya seeds is affected much more by external conditions than by internal conditions. Germination of cherimoya variety ‘Concha Lisa’ were tested for germination at constant temperatures of 25, 30, 40°C, and at room temperature, varying from 20-25°C, coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water), for 25 days of incubation. The kinetics of germination was determined according to five closely related parameters, viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), time to 50% germination (T50) and seedling length (SL). The temperature of 30°C was found optimally suitable with 70.8% FGP, 17.5 days MGT and 3.91 cm SL, while the room temperature of 20-25°C slightly improved germination with only 25% FGP. Furthermore, significant decrease in FGP and SL was observed at 25°C and 40°C of temperature in comparison to 30°C. The analysis also revealed that cherimoya seed germination, day 10-15 after seed sowing is suitable for final counts. An overview on the emergence of cherimoya seedlings, during a 12-week period in pots is presented.

Keywords: agriculture; Annonaceae; custard apple; exotic fruit; fruit tree; seed quality.

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Effect of Cold Stratification on Seed Germination of The Multipurpose Fruit Shrub, Ziziphus Lotus (L.) LAM. (Rhamnaceae)

A. Kheloufi, L.M. Mansouri, K. Laib

ABSTRACT. Shrubs and trees of the genus Ziziphus are a good example of naturally occurring multipurpose plant species with great potential in arid regions. This study was conducted to investigate the effect of cold stratification on seed germination and seedling growth of Ziziphus lotus (L.) Lam. Seeds were subjected to 0, 45, 90 and 120 days of cold stratification at 5°C. We also examined fruit, kernel and seed morphology. For each treatment period, four replicates of 50 seeds were incubated in plastic containers between two layers of moist sand at 15% and under greenhouse conditions for 15-day period. At the end of the experiment, the final germination percentage (FGP), shoot length and root length were assessed. The results clearly indicated that increasing duration of cold stratification improved seed germination. The most effective stratification period was 120 days where Z. lotus recorded 83% of FGP and 16.5 cm of total seedling length. Cold stratification treatments significantly increased shoot height, root length, as well as seedling total length. 120 days stratification treatment resulted in the highest shoot and root length (6.80 cm and 9.75 cm, respectively). An overview on the emergence of Z. lotus seedlings during a 15-day period was also illustrated.

Keywords: agriculture; arid region; buckthorn; Jujube; medicinal plants; seed quality.

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Effect of Nitrogen Fertilizer on Growth, Flowering, Fruiting and Nodulation of Three Varieties of Common Bean in The Arid Region of Aïn Naga (Biskra, Algeria)

L.M. Mansouri, A. Kheloufi, R. Belatreche, N. Heleili, Z.F. Boukhatem

ABSTRACT. Field experiments were conducted to investigate the response of common bean (Phaseolus vulgaris L.) to nitrogen fertilizer. The main factor included the fertilizer (Granular Urea 46% N), was made up of two levels: no fertilization (0 kg/plot: control) and fertilization (0.4 kg/plot), while the secondary factor was the variety (three varieties of common bean: Djedida, Nelson and Jalila). The experimental design was a randomized complete block design with split plot arrangement and replicated four times. The effect of fertilization was evaluated during two development stages (flowering and fruiting) for each variety and this on the total dry biomass, the length of the aerial and root parts, as well as on the number of secondary roots. On the other hand, the combined effect of fertilization and variety was studied on some yield parameters per plant, such as the number of flowers, pods, seeds and the harvest index. In addition, the number of nodules at the end of seed maturation was evaluated. The results indicated that the nitrogen fertilizer application significantly reduced the root length, the number of nodules and secondary roots in most of the common bean varieties. However, fertilizer application significantly increased dry matter in both flowering and fruiting stages, for the three studied varieties. Pod number per plant and seed yield was increased by the application of N fertilizer, depending on varieties and the parameters being measured. Djedida and Jalila varieties gave the best yield and can therefore be recommended to farmers. According to our results, the percentage of improvement by N fertilization on one parameter or another does not exceed an average of 20%, compared to the control. Indeed, the effect of fertilization is positive and seems to increase the harvest index by 18% in Djedida and by 20% in Jalila, compared to non-fertilized plants. Unfertilized plants of the variety Nelson showed the highest ability to nodulate.

Keywords: agriculture; dry matter; crops; Fabaceae; Phaseolus vulgaris; yield.

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