Germination Test of Cherimoya (Annona cherimola Mill.) Under abiotic constraints in Laghouat region

Abstract

The main objective of this work was to study the germination and emergence of Annona cherimola Mill in Laghouat region. It was interested in the study of primary dormancy in the first time, but also on seed germination behavior to cope with some abiotic factors, in emergence, as well as in the conservation of their viability. We used physical methods and evaluated the results by the parameters of germination and modeling as well as states for carrying out this study. The final germination percentage (FGP): for Storage seeds (FGP Floationg= 0% and FGP= 3.34% Soaking), for Fresh seeds (FGP Floationg = 10% and FGP Soaking= 60%). The results of the Effect of storage of cherimoya seeds on germination show that the storage duration of A.cherimola seeds does not exceed 4 years. The results of germination fresh seeds: germination of 50 % seeds soaking and 20% seeds floating in box. Germination 75% of seeds soaking and 15% seeds floating in soil. Germination of 80% seeds soaking and 50% seeds floating in compost. The first seeds germinated in compost after 10 days, The first seeds germinated in soil after 18 days. The first seeds germinated in box after 15 days. The results of the parameters germination test were measured over an incubation period of 25 days during the experimental period are (FGP=50%), (MGT= 16.45 days), (CVG= 5.88%), time to 50% germination (T50=17.73 days) of A. cherimola. on box. On soil the final germination percentage (FGP=80%), Final germination percentage (FGP=75%), mean germination time (MGT= 4.58 days), coefficient of velocity of germination (CVG= 7.14%), time to 50% germination (T50=6.25 days) of A. cherimola. Mean germination time (MGT= 8 days), coefficient of velocity of germination (CVG= 4.54%), time to 50% germination (T50=7.78 days) of A. cherimola on compost. The results of the effect temperature parameters on germination in box: A first period of latency (Tmin=10 to13°C. Tmax=25.4°C), a second exponential period where germination is accelerated (Tmin=10 to18°C. Tmax°C=33.8°C) and a stationary phase (Tmin=10 to 22°C. Tmax= 35°C). Germination in soil: A first period of latency (Tmin=10 to 20°C. Tmax= 30.1°C), a second exponential period where germination is accelerated (Tmin=22°C. Tmax=31°C) and a stationary phase (Tmin=21°C. Tmax= 32.2°C). Germination in compost: A first period of latency (Tmin= 10 to 19°C Tmax=33°C), a second exponential period where germination is accelerated (Tmin=12.8°C. Tmax=22.5°C) and a short and limited stationary phase (Tmin=23°C. Tmax= 33°C). We use the mathematical formula of YAN and HUNT (1999). The results of the non-linear regression of temperatures applied to the number of germinations in the different cherimoya germination trays of the period (May 1 to June 6, 2024) are Tmin=10°C a Tmax=38°C. Fresh seeds exhibit variable behaviors (P<0.0001) at minimum temperature and (p<0.0001) at maximum temperature at room temperature.