Investigation of the impact of hand pollination on the yield of African horned cucumber (Cucumis metuliferus E. Mey. Ex Naudin) under protected structures

Abstract

Most growers prefer enclosed crop production over open space crop production to mitigate environmental conditions such as excessive rainfall, wind and hail. However, there is limited access to natural pollination agents like wind and bees when crops are grown in protective structures where pollination challenges arise. This study was conducted for two seasons in 2021 and 2022 to investigate the impact of hand pollination on the yield of African horned cucumber (Cucumis metuliferus E. Mey. Ex Naudin) grown under protective structures such as a greenhouse or under shade netting. Plants grown under these enclosed environments were hand pollinated in the morning during the flowering stage, where pollen was manually transported from the male to the female flowers on the same plant using fresh earbuds (selfing). The study results showed that in comparison to cultivation under shade netting, hand pollination was associated with at least a doubling in cucumber fruit number and up to a seven-fold increase in ripe fruit number in plants cultivated in the greenhouse compared to control plants grown under shade netting without hand pollination. Furthermore, the combination of hand pollination and greenhouse cultivation improved the harvest index from 0.11 to 0.35 kg over the control plants. In summary, the findings of this study support the use of hand pollination to increase the yield of African horned cucumber in growing environments such as shade netting and this increase in yield is particularly improved in plants cultivated in a greenhouse. Thus, growers are encouraged to employ hand pollination to improve cucumber crop yield and to maximise profits.

Abalimi abaningi bakhetha ukukhiqizwa kwezitshalo okuvalekile kunokukhiqizwa kwezitshalo endaweni evulekile ukuze kuncishiswe izimo zemvelo ezifana nemvula enkulu, umoya nesichotho. Kodwa-ke, izinselelo zokuvuthwa kwempova ziyavela njengoba kukhona ukufinyelela okulinganiselwe ezimpoveni zemvelo njengomoya nezinyosi lapho izitshalo zitshalwa ezakhiweni zokuzivikela. Lolu cwaningo lwenziwa ezikhathini zonyaka ezimbili ngo-2021 nango-2022 ukuze kuphenywe umthelela wempova yezandla esivunweni se-African horned cucumber (Cucumis metuliferus E. Mey. Ex Naudin) etshalwe ngaphansi kwezakhiwo zokuzivikela ezifana nezakhiwo zengilazi noma ngaphansi kwenethi elinomthunzi. Izitshalo ezitshalwe kulezi zindawo ezivalekile zafakwa impova ngesandla ekuseni ngesikhathi sokuqhakaza, lapho impova yayithuthwa ngesandla isuka kweyeduna iye ezimbalini zesifazane esitshalweni esifanayo kusetshenziswa okuncane okusha okufakwa endlebeni (ukuvundiswa ngempova esitshalweni esifanayo). Imiphumela yocwaningo ibonise ukuthi uma kuqhathaniswa nokutshalwa ngaphansi kwenethi elinomthunzi, ukuvuthwa kwempova ngesandla kuhlotshaniswa okungenani nokuphinda kabili kwezinombolo zezithelo zekhukhamba kanye nokukhuphuka okuphindwe kasikhombisa kwezinombolo zezithelo ezivuthiwe ezitshalweni ezitshalwa ezakhiweni zengilasi uma kuqhathaniswa nezitshalo zokulawula ezitshalwe ngaphansi kwenethi elinomthunzi ngaphandle kwempova yezandla. Ngaphezu kwalokho, inhlanganisela yempova yezandla kanye nokutshalwa kwezakhiwo zengilasi kwathuthukisa inkomba yokuvuna isuka ku-0.11 kuya ku-0.35 kg ngaphezu kwezitshalo zokulawula. Kafushane, okutholwe kulolu cwaningo kusekela ukusetshenziswa kwempova yezandla ukuze kwandiswe isivuno se- African horned cucumber ezindaweni ezikhulayo ezifana nomthunzi wenethi futhi lokhu kwanda kwesivuno kuthuthukiswa ikakhulukazi ezitshalweni ezitshalwa ezakhiweni zengilasi. Ngakho-ke, abalimi bakhuthazwa ukuba basebenzise impova yezandla ukuze bathuthukise isivuno sesitshalo sekhukhamba kanye nokwandisa inzuzo.

Balimi labaningi bakhetsa kukhicitwa kwetitjalo lokuvalekile kunekukhicitwa kwetitjalo endzaweni levulekile kute kuncishiswe timo temvelo letifana nemvula lenkhulu, umoya nesangcotfo. Kodvwa-ke, tinselela tekuvutfwa kwemphova tiyavela njengobe kukhona kufinyelela lokulinganiselwe kuma-ejenti emvelo ekutfutsa imphova njengemoya netinyosi lapho khona titjalo titjalwa etakhiweni tekutivikela. Lolucwaningo lwentiwe kumasizini lamabili nga-2021 nanga-2022 kuze kuphenywe umtselela wemphova yetandla esivunweni sekhukhamba yase-Afrika (Cucumis metuliferus E. Mey. Ex Naudin) letjalwe ngaphasi kwetakhiwo letivikelako njengendlu lebamba kushisa nobe ngaphansi kwemtfunti wenethi. Titjalo letitjalwe kuletindzawo letivalekile tafakwa imphova ngesandla ekuseni ngesikhatsi sekuchakata, lapho imphova yayitfutfwa ngesandla isuka kulendvuna iye etimbalini tesifazane esitjalweni lesifanako kusetjentiswa ema-earbuds lamasha (selfing). Imiphumela yelucwaningo ibonise kutsi uma kucatsaniswa nekutjalwa ngaphasi kwenethi lenemtfunti, kutfutfwa kwemphova ngesandla kuhlotjaniswa lokungenani nekuphindza kabili kwetinombolo tetitselo tekhukhamba kanye nekukhuphuka lokuphindvwe kasikhombisa kwetinombolo tetitselo letivutsiwe etitjalweni letitjalwa ku-greenhouse uma kucatsaniswa netitjalo tekulawula letitjalwe ngaphasi kwemtfunti wenethi ngaphandle kwekwentiwa kwemphova ngesandla. Ngetulu kwaloko, inhlanganisela yemphova yesandla kanye nekutjalwa kwe-greenhouse kutfutfukiswe inkhomba yekuvuna kusuka ku-0.11 kuya ku-0.35 kg ngetulu kwetitjalo tekulawula. Kafishane, lokutfolwe kulolucwaningo kusekela kusetjentiswa kwemphova yetandla kute kwandziswe sivuno sekhukhamba yase-Afrika etindzaweni tekukhulisa letifana nemtfunti wenethi futsi lokwandza kwesivuno kutfutfukiswa ikakhulukati etitjalweni letitjalwa endzaweni lebamba kushisa. Ngako-ke, balimi bakhutsatwa kutsi basebentise imphova yetandla kute batfutfukise sivuno sesitjalo sekhukhamba futsi nekwandzisa inzuzo.