Morphological, physiological and yield response of maize (Zea mays L.) to seed treatments

Abstract

English: Increasing crop yields for an ever growing world population has currently become a topic of great importance for agronomists and plant physiologists alike. The main objective is to find the cheapest and most effective methods to obtain this goal. In this regard seed treatment is one of the approaches that offer great potential. With this in mind, the underlying study was undertaken in order to test a range of products including prototypes and commercially available products. During the laboratory and glasshouse screening phases optimal concentrations for the plant growth regulators ComCat® (25 mg kg-1 seed) and SS (12.5 mg kg-1 seed) were identified in terms of seedling growth response. Additionally, the two fertilizer products Teprosyn® and Seniphos® initially showed promise in this regard when applied on their own or in combination with the plant growth regulators and the uptake enhancer AnnGro™ . However, of all the seed treatments and purely based on the eventual marked yield increase obtained, ComCat® (+500 kg ha-1) on its own and Teprosyn® in combination with SS and AnnGro™ (+800 kg ha-1) proved to be the most promising. Although the metabolic response of maize seedlings to the different seed treatments were followed in terms of selected events, no clear picture emerged in terms of the mechanisms of action underlying the eventual yield increase. It became clear that this aspect needed special attention in a follow-up study over a total growing season. From this study it is recommended that ComCat® on its own as well as the Teprosyn®/SS/AnnGro™ combination treatment can be considered strongly as seed treatments of maize under rain fed conditions, but this should be followed over more seasons. This recommendation is purely based on the consistent enhancing effect that both treatments revealed in terms of seedling growth and final yield. The potential of these treatments should also be evaluated under irrigation conditions.

Afrikaans: Die verhoging van oesopbrengs in ‘n verskeidenheid van gewasse gemeet teen die agtergrond van ‘n ewig groeiende wêreldbevolking is huidig ‘n belangrike onderwerp onder beide agronome en plantfisioloë. Die hoofdoel is om die goedkoopste maar doeltreffendste metodes te vind ten einde hierdie doel te bereik. In hierdie verband is saadbehandeling een van die benaderings wat groot potensiaal toon. Met laasgenoemde in gedagte is hierdie studie onderneem en met die hoofdoel om ‘n reeks produkte, insluitende prototipes en kommersieël beskikbare produkte, in hierdie verband te toets. Gedurende die aanvanklike laboratorium en glashuis siftingstoetse is optimum konsentrasies vir die plantgroeireguleerders ComCat® (25 mg kg-1 saad) en SS (12.5 mg kg-1 saad) in terme van saailing groeirespons geïdentifiseer. Addisioneel het die twee bemestingsprodukte Teprosyn® en Seniphos® aanvanklik potensiaal in hierdie verband getoon toe hulle op hulle eie of in kombinasie met die plantgroeireguleerders en die opname verhoger AnnGro™ as saadbehandelings toegedien is. Maar van al die saad behandelings, en suiwer gebaseer op die finale oesopbrengsverhoging wat verkry is, het ComCat® (+500 kg ha-1) op sy eie en Teprosyn® in kombinasie met SS en AnnGro™ (+800 kg ha-1) die hoogste potensiaal getoon. Alhoewel die metaboliese respons van mieliesaailinge op die verskillende saadbehandelings in terme van geselekteerde momente gevolg is, kon geen gevolgtrekking gemaak word met betrekking tot die aksiemeganismes wat die uiteindelike verhoging in oesopbrengs voorafgegaan het nie. Dit het duidelik geword dat hierdie aspek spesiale aandag moet geniet in ‘n opvolgstudie en oor ‟n volle groeiseisoen. Uit die resultate wat met hierdie studie bekom is word aanbeveel dat ComCat® op sy eie sowel as die Teprosyn®/SS/AnnGro™ kombinasie behandeling sterk oorweeg word as saadbehandelings van mielies onder droëland toestande oorweeg word. Hierdie aanbeveling is suiwer gebaseer op die konsekwente verhogingseffek wat beide behandelings op saailinggroei en oesopbrengs getoon het. Die potensiaal van hierdie behandelings onder besproeiingstoestande behoort ook geëvalueer te word.